The ESS Accelerator has reached another groundbreaking milestone as cold RF conditioning is getting started under operational conditions at 2 K. This critical phase marks the culmination of years of effort and collaboration, bringing the project closer to its goal of delivering high-energy proton beams to the Target.
After successfully having cooled down the cavities of all 27 cryomodules and the cryogenic distribution system to 4 K, the focus now shifts to the next crucial step: RF power conditioning at 2 K (-271 degrees Celsius). At this ultra-cold temperature, the cavities become superconducting. This means they can conduct electricity without resistance, dramatically increasing their efficiency and allowing the accelerator to operate with minimal energy loss. This phase will prepare the cavities for full accelerator commissioning with beam by conditioning them with radio-frequency (RF) power from the Klystron Gallery power sources. This requires not only ensuring that all technical systems are prepared for this phase but also fulfilling the necessary formal and regulatory requirements, including obtaining the system permit and beam authorisation approval.
The 4 K cooldown, a key preparatory phase, was completed as planned under the supervision of the Local Control Room, in collaboration with the Accelerator, Integrated Control Systems (ICS), and Main Control Room teams. These groups maintained round-the-clock shifts and on-call duty to ensure the seamless execution of this complex process, which was guided by an Automatic Control Sequence developed by the SRF (Superconducting RF) and ICS teams.
With the accelerator operating under cold and stable conditions, ESS is on course for commissioning the entire accelerator: In the first quarter of 2025 the plan is to send the proton beam from the Ion Source, through the Superconducting Linac, and to the Tuning Beam Dump at the end of the tunnel.
Follow the cooldown progress live via the ESS Public Operations Screen.
This article is part of the series "Road to Beam on Dump" where we highlight all the systems required to commission the ESS accelerator.
Previous updates:
- Accelerator Magnets Ready for Beam
- Warm Coupler Conditioning Completed - ESS Accelerator Prepares for Cold Operation
- ESS Linac Under Vacuum
- The Power to Accelerate: RF Power Stations up and running
- Installation and Testing of the 2 MW RF Scope Completed
- Focus on Beam Instrumentation: Completion of Beam Current Monitors Installation in the ESS Accelerator
- First Insertable Beam Stop installed in the ESS superconducting linac
- Magnets Ready to Focus and Steer the Proton Beam
- Warm Coupler Conditioning starts in the ESS Superconducting Linac